The new variety of rose plant of the present invention originated from a controlled crossing in a breeding program of two distinct parents during the summer of 1992. The crossing was between ‘Margaret Merrill’, a non-patented rose and an un-named seedling.
The resulting seeds were planted during the following winter. The resulting seedlings were evaluated and exhibited distinctive physical and biological characteristics. The new rose plant was selected as a single plant from the seedling beds due to its superior characteristics and asexually propagated for further evaluation. This new and distinctive rose variety is named ‘KORgretaum’.